\section{Introduction}

Today, social media is has become an integral part of day-to-day life. This includes services such as online social networks, micro blogging services etc. Furthermore, we have already seen the power of such tools in situations such as broadcasting opinions. This automatically leads way to censorship and suppression by political forces. Such control is feasible due to the current architecture of these services where they primarily adopt a client-server model. It is interesting to see different approaches in which we can maintain the power of social media while being able to resist control by third parties.

In this work we consider a peer-to-peer setup where the peers are \emph{only} connected to other peers who they personally trust. These are called $contacts$ of a peer. A peer distributes a message to its contacts (which we call an $update$) and all the peers are expected to receive this update. A peer may directly communicate the message when a contact is available online. We address the problem where there is only a sub set of contacts available to a peer to directly communicate a message and the other peers needs to obtain this message from those who have already possess it without compromising their privacy. We present a novel cryptographic approach as a solution to this problem.

Following section introduces the setup of the network of peers and how they are connected and the requirements that we try to satisfy with our scheme. This is followed by the preliminary notions and then we describe our solution that meets the stated requirements. Implementation of the proposed cryptographic primitives is presented in the solution section followed by future directions of this work and conclusion.
